Is dtomsetthotmail a real email address?

Answer 1

No. Real e-mail addresses have a username followed by an @ symbol followed by a domain followed by a top-level domain. For instance, myusername@mydomain.com would be considered a valid e-mail address for someone in the mydomain domain. However, just because the address appears valid does not mean the address actually exists. The only way to find out is to send an e-mail to the address. Even so, unless you get a response there's no way to tell if the address is actually in use. Non-existent addresses will time-out after several unsuccessful attempts to deliver your message.